Group question on machining something

Whats the best way to make a square hole in a round piece of material,
without a broach? The round rod needs to be split, so it can be
placed over a 5/8 square rod, and then be able to slide along that
square rod
The problem: I need a round bar, with a 5/8" square hole in the
center, to go over the square "run fowards/stop/run reverse" rod that
runs the length of the bed, under the acme threading screw, and the
feed rod.
The lathe is missing the run/stop/reverse lever and assembly, so I
want to make one. Pretty simple..but Ive been banging my head over
the best way to make something that simple. I finally did accomplish
it..but it was a serious pain in the ass.
I ultimately milled a half depth 5/8 wide groove in a 5" long chunk of
scrap stock, cut it in half so I had two halves, then milled all sides
so it was semi square, then chucked it in a 4 jaw, indicated on a 5/8
round stock slipped into the square hole, then turned to
diameter,about half the lenght, then removed, then put into a 3 jaw,
clamping on the already turned secton, then re-turned the last half to
match the first.
There has to be an easier way ( the shaper blew a drive belt..so its
on the Fix list)
This round with square hole gizmo..will be installed inside of a bore
that will be bolted to the bottom of the carraige, with the
run/stop/reverse rod running throuigh it. The assembly will remain
fixed..the round with square, will be the actuator for the swtich
rod..using a handle
Gunner
"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you
for torturing the cat." Gunner
Reply to
Gunner Asch
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Damn, your life's a bitch! What did you do, stomp God's puppy?
I think a construct is the only way to go, sometimes you can make a "Frankenpart" from bits of other pieces of crap. An old, old Hungarian machinist tought me as a kid: "First learn how to weld anything and here's a file and a hacksaw." "But, I want to learn machining!" "You learn that file, hacksaw and welding and you'll KNOW machining."
Reply to
Tom Gardner
"Tom Gardner" wrote: (clip) "You learn that file, hacksaw and welding and you'll KNOW machining." ^^^^^^^^^^^^^^^^^^ I think Tom has the right idea. But I'll be more specific. Hack saw or band saw the round bar to the required depth. Heat it red hot with your acetylene torch, and hammer it around the square piece that you want it to fit. Drill a hole to accept the clamp screw. If necessary, turn the outside round in one of your many lathes.
Reply to
Leo Lichtman
1. Careful chain drilling (tiny bit in corner) followed by either die filer or hand filing
2. Drill a slightly oversized hole and use a boring bar with a specially ground bit to stroke 4 square corners (you can stroke a few thou off cranking the apron back and forth on a lathe, or cranking the spindle up and down on a mill)
3. Break small bandsaw blade, drill hole, pass blade through material, weld up, bandsaw square hole, break blade again, remove part
4. Suck up to someone with an EDM machine
5. If you're good, hot punch a square hole using blacksmithing techniques, then grab the part by the hole on a square mandrel, and turn the outside round and concentric
GWE
Gunner Asch wrote:
Reply to
Grant Erwin
Take two square bars and mill a 5/8ths slot in each. Put together and braze one end together. Chuck un-brazed end in 4-jaw chuck and turn to suit. Flip around a face off. Flip again cut off to length.
Might not be perfect but what do you expect for free advice?
Reply to
Mike
Pretty much what I did, except I used hose clamps...chuckle Ill post some pics later in my yahoo album
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
Reply to
Gunner Asch
Use your plasma cutter you bought at H.F. I suppose if I was on welfare I would shop there to

Reply to
tony stramella
Gunner, I know you would probably rather make your own, but these things are readily available from Green Bay Manufacturing:
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Dennis
Reply to
DT
Gee, all that work for a $8.60 part! Steve
Reply to
Steve Lusardi
I had a similar poblem last year: How to make keyways on a lathe without a broach or a mill. I got some HSS tool blanks and ground one to size. Then I put the work in the 3 jaw and set the back gear to a high ratio so it would be dificult to turn from the chuck (sort of like using the back gearing as a brake). Then I set the tool in the tool post and used the saddle wheel to "broach" the keyway a few thou at a time with the key at the 9:00 position looking at the chuck. It was slow work, but worked great.
Reply to
Kelly Jones
Put the piece in the forge. Heat to a bright red heat. Punch out with a square hot punch. Time consumed, one minute +/-. You do have to fire up the forge though. Happy new year. Bugs
Reply to
Bugs
I'm not sure if they have one the right size, but I'd cheat and see if I could buy a sleeve pre-bored from Reid Tool. They sell round sleeves with square holes in a variety of sizes.
Doug White
Reply to
Doug White
I would start with the aforementioned (in two posts no less!) 'lathe as shaper' approach.
Basically bore a somewhat oversized hole in the round, and then put the 'corners' in with a shaper-type bit in the toolpost by stroking with the carriage.
The end result does not have to be truly, completely square, it only has to have square corners. Boring it oversized to start reduces the amount of material that has to be 'shaped' off drastically.
Jim
Reply to
jim rozen
My, my, aren't we full of cute comments.
You, sir, are a pain in the ass.
Harold
Reply to
Harold and Susan Vordos
Hey Gunner,
Not really sure why you want to do exactly what you describe, but for the accuracy I suspect you need, or lack there-of in fact, I have two suggestions.
A piece of 3/4 X 3/4 X 1/8 angle, cut to length twice, weld each into a suitable round also sliced lengthwise in half.
or
Just use the round with a round hole that the drive shaft will fit through, and put four set-screws cross-ways, or if it's longer than I imagine, put 4 in each end, to form the "square" drive.
Take care. Happy New Year.
Brian Lawson, Bothwell, Ontario. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Reply to
Brian Lawson
What plasma cutter?
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
Reply to
Gunner Asch
Well dip me in shit. Saved for further reference. Thanks much. Though I dont think much of leadloy for this application, its a GREAT link!
They are a bit pricy on their acme nuts..but not terribly so. Im getting ready to start repairing the litle horizontal/verticle Hales/Yamazon/Red Dragon Noodle and Machinetool Collective miller and they have at least half the nut I need.
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
Reply to
Gunner Asch
And -- even *with* a broach -- you have to bore slightly oversized, to match the pilot end.
Enjoy, DoN.
Reply to
DoN. Nichols
I DO have a shaper. The drive belt busted. No biggie...$8 or so..but I wanted to do this an alternative way.
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
Reply to
Gunner Asch
snip--
Oh, yeah! It's not that it can't be welded, but more so that when folks like us weld on it, we're asking for cracks or other problems. When it's welded to MIL specs, how it's handled is ultra critical, and must see a heat treat oven in short order.
Just a caution that welding on it like it's mild steel can yield certain surprises, including a weld so hard you can't do anything with it if necessary, aside from grinding. Hell, you can weld cast iron with 7018------it just doesn't turn out too well.
Harold
Reply to
Harold and Susan Vordos

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